isVisible.js

// true if display none or visibility hidden
function isVisible(el) {
    var style = window.getComputedStyle(el);
    return (style.display !== 'none')
}

// return true if element is in the window bounds or false if outside
function isInWindow(el) {
	var viewportOffset = el.getBoundingClientRect();
	// these are relative to the viewport
	var top = viewportOffset.top;
	var right = viewportOffset.right;
	var bottom = viewportOffset.bottom;
	var left = viewportOffset.left;


	topInWindow = top > 0 && top < window.innerHeight;
	bottomInWindow = bottom > 0 && bottom < window.innerHeight;

	leftInWindow = left > 0 && left < window.innerWidth;
	rightInWindow = right > 0 && right < window.innerWidth;

	console.log("topInWindow", topInWindow);
	console.log("bottomInWindow", bottomInWindow);
	console.log("leftInWindow", leftInWindow);
	console.log("rightInWindow", rightInWindow);


	return (topInWindow || bottomInWindow) && (leftInWindow || rightInWindow);
}